In-vitro Virucidal and Anti-adsorption Activities of Dried Flowers Extract of Aegle Marmelos against Dengue Virus Type 1

Abstract

Dengue is an arbovirus infection that contributes to a significant health problem in tropical and subtropical countries. Aqueous extract of Aegle marmelos dried flowers (Bael flower drink) is a popular fever remedy used in Sri Lankan traditional medicine. The present study aimed to investigate in vitro direct virucidal activity and anti-adsorption activity of flower extract obtained from Aegle marmelos. Traditional decoction of the dried flowers’ aqueous extract was prepared by reducing eight volumes to one volume. The decoction was freeze-dried and used. Additionally, C6/36 cells were infected to propagate the dengue virus type 1 and Vero cells were used to quantify the infectious virions via Plaque assay. Dulbecco's Modified Eagle Medium: Nutrient Mixture F-12 was used as the culture medium. The flower extract was added to the cell culture medium and incubated at 37°C in the presence/ absence of dengue virus for 3 hours. Virions were quantified in one-hour intervals to determine the virucidal activity of the flower extract. The virus was adsorbed to Vero cells in the presence/absence of flower extract and virions were quantified to determine the anti-adsorption activity. Results were statistically analysed using GraphPad Prism software. During 0, 1, 2 and 3 hours post-incubation with the flower extract, the virus was significantly inhibited (p < 0.05) at an average percentage inhibition of 46.48%, 39.59%, 26.17% and 35.06% respectively. The flower extract had significant (p < 0.01) anti-adsorption activity displaying 62.58% percentage virus inhibition in Vero cells. Aegle marmelos dried flowers’ aqueous extract is a viable candidate for identifying anti-dengue viral compounds with direct virucidal and anti-adsorption activity. Also, this extract would be a potential source to isolate biologically active compounds that can inhibit the early stages of the dengue life cycle and it could exert prophylaxis effects against the dengue virus.